In consideration of information security, it is more and more common to impart a user-verifying function to an electronic device, and more particularly to a portable device such as USB drive, smart phone, notebook computer, personal digital assistant (PDA), etc., which is subject to loss. Generally, the user-verifying function is performed by way of biologic feature check, e.g. fingerprint check.
Please refer to FIG. 1A, which schematically shows the appearance of a smart phone, and FIG. 1B, which illustrates the flowchart of a conventional fingerprint-verifying process applied to the smart phone. After a user switches on the power of the smart phone 100 and a booting process is executed, a prompt window pops up on the display 10 (Step 101), instructing the user to perform fingerprint check through an optical sensor 11 disposed on the phone 100. After the optical sensor 11 finishes scanning the user's fingerprint and acquires a corresponding fingerprint data (Step 102), the fingerprint data is compared with a previously stored fingerprint data (Step 103). If a comparable result is obtained, the smart phone enters a normal operation mode (Step 104) so as to allow the user to normally operate the phone 100. Thus the user may input commands via a push button 12 as shown in FIG. 1A or the display 10 when it is a touch screen. On the contrary, if the acquired fingerprint data does not conform to the previously stored fingerprint data, the smart phone 100 enters a locked mode so that the input means is disabled from normal command input (Step 105).
As the fingerprint-verifying procedure has to be conducted to unlock the phone before a user may successfully operate the phone, it is troublesome and time-consuming to general users.